This invention relates to rainwater guttering systems for roofs of buildings, and is particularly concerned with a method and apparatus for preventing the blockage of internal corner roof gutters located at the bottom of valley gutters.
A roof valley is the region where two inclined roofs meet. This region has a substantially V-shaped cross-sectional configuration and generally slopes in one direction toward the edge of the building. A metal tray or gutter is located in the roof valley to collect water flowing from the roof cladding and to direct the water to a roof gutter. During downpours, very large volumes of water and debris can be collected from the roof and wash down into the roof gutter. The design of the roof gutter is such that the flow from the valley gutter is split in half, with one portion going with the flow in the roof gutter and the other portion being pushed against the flow. This can create blockage in the roof gutter if debris is present, and cause a back-up of water invariably leading to overflow and, in some instances, internal water damage to the building.
It is therefore an object of this invention to provide a satisfactory solution to the aforementioned problem or to at least provide the public with a useful alternative.
According to one aspect of the present invention there is provided a method for preventing the blockage of an internal corner roof gutter to be located at the bottom of a valley gutter, which method comprises the steps of:
(i) Transversely cutting a rear wall and base of a roof gutter, in which an internal corner is to be formed;
(ii) bending the gutter at right angles at the cut so as to produce an opening in the base and rear wall thereof;
(iii) fixing the roof gutter to an internal corner of a building fascia or other support means; and
(iv) fitting a rainwater head with attached downpipe to the internal fascia or other support means, so as to extend at least partly below the roof gutter opening.
The rainwater head comprises a second aspect of the invention.
According to this second aspect of the present invention there is provided a rain head for fitting beneath a roof gutter located at an internal corner of a building, said rain head having a substantially quadrangular or triangular cross-sectional configuration to enable it to be snugly located between the relatively perpendicular walls defining the internal fascia or other support means for the roof gutter, the said rainhead including a compartment with an upwardly facing inlet and a downwardly facing outlet, said inlet incorporating a primary screen which is supported in such a manner as, in use, to deflect debris away from the compartment whilst permitting water to flow through it and into the compartment for discharge through the outlet.
The compartment can optionally include a secondary screen located between the primary screen and the outlet, to prevent the ingress of vectors such as mosquitoes to the outlet. Such a secondary screen is mandatory to meet government requirements if used in conjunction with the catchment and storage of rain water.
Preferably, the internal corner rain head will include flanges projecting upwardly from two adjacent sides to enable connection to the fascia or other support means by screws, nails or like fixing arrangements. Such flanges also act as xe2x80x9ca splash backxe2x80x9d to prevent the fascia from water damage.
The primary screen is typically angled so that the majority of rainwater and debris hits the screen as it falls through the gutter at between about 45xc2x0 and 60xc2x0. This angle is skewed towards 45xc2x0 for light rainfalls and towards 60xc2x0 for high rainfalls by notching the upper edge of the primary screen upwards or downwards while maintaining the bottom edge of the screen in a fixed location. The screen can be manufactured from a range of non-corrosive materials such as plastics material, metal, composites, or a combination thereof. Powder coated galvanised iron stranded screens are particularly suitable as they enable the maximisation of the open spaces in the screening surface while simultaneously breaking any water capillarity in the openings. Preferred sizes for the openings in the primary screen are between 4xc3x974 mm and 9xc3x979 mm, most preferably about 6xc3x976 mm.
The secondary screen when present can be manufactured from a similar range of materials to the primary screen. Preferably, however, it is manufactured from welded or wire woven stainless steel, zincalum, galvanised steel, brass, copper or fibreglass. The mesh size can typically be 0.9xc3x970.9 mm and can include an appropriate support framework to enable retention of shape and ease of placement. A particularly preferred framework comprises a rectangle of plastics material in which the screen is embedded during the production thereof. Finger extensions are provided on opposing edges of the framework to enable the secondary screen to be placed in, and removed from, a recess which snugly holds the secondary screen when it is press-fitted therein.
In a further modification, the internal corner rain head can be designed to include a projection formed on its unattached peripheral side which which extends upwardly to the same height as the outer face of the roof gutter, so as to, in effect, extend across the corner of the roof gutter and thereby provide an attractive finish to the product.
The internal corner rain head permits the unimpeded flow of water and debris from the valley tray directly through the opening in the roof gutter and to the rain head, thereby obviating any blockage in the roof gutter and hence avoiding overflow and potential water damage to the building.